Electric motor.



No. 669,759. Patented Mar. I2, |90l.

' C. MILDE.

,f ELECTRIC MOTOR.

(Application led Aug. 22, 1900.1 y (nu Modem 2 Sheets-Shui l.

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No. 669,759. Patented Mar. I2, I90l.

' C. MILDE.

ELECTRIC MOTOR.

(Application led Aug. 22. 1900. l

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UNITED STATES CHARLES MILDE, OF PARIS, FRANCE, ASSIGNOR TO STE. CI-I. MILDE PATENT CEEIcE.

FILS

ET CIE., OF SAME PLACE.

ELECTRIC M OTO R.

(ZFEGIFIGATION forming part of Letters Patent No. 669,7 59, dated March 12, 1901.

` Application filed August 22, 1900. Serial No. 27,668. (No model To @ZZ Ifo/tom, 1li; may concern:

Beit known that I, CHARLES MIL'D, a citizen of the Republic of France, residing in Paris, France, have invented certain new and useful Improvements in Electric Motors, of which the following is a specification.

This invention relates to an electric motor for vehicles, which may be termed a difterential electric motor.

It comprises two armatures keyed to two independent shafts, each driving a wheel of the vehicle, the magnetic fields ot these armatures being symmetrical and in equilibrium.

In the accompanying drawings, Figure 1 is a longitudinal vertical section of the motor on line X X' of Fig. 2, and Fig. 2 is a transverse section on line Y Y of Fig. 1. The other figures are diagrams showing the ind ucing-coils and the magnetic circuits, Fig. 3 being an'elevation, Fig. 4; a plan from below, Fig. 5 an end view looking to the left, and Fig. 6 an end View looking to the right. Figs. 7, 8, and 9 are diagrams of the connections between the motor, commutator, and generator.

The preferred construction of the di'iterential motor of myinvention is as follows: rlwo similar brackets of diamagnetic material F, provided with lugs E for fixing them to a support, carrying each a cast-metal frame C, to which is fixed a plumber-block P, carrying a bush d. Four steel rods B are supported at their ends in these brackets, the ends being screwed to receive nuts for holding the bars rigidly to the brackets. These bars support midway between the brackets a plumberblock P, having two bushes cl' d. The four bars constitute the cores of the exciting-coils, of which each bar carries two D T, one on each side of the central plumber-block. Each bar also carries two pole-pieces M, one near each bracket F. These pole -pieces nearly surround two similar ring or drum armatures A A, the collectors `c c of which are in the frames C. The shafts, to which the armatures are keyed, turn in the bushes d d of the end plumber-blocks, through which bushes their ends p p protrude for connection with driving-gear and in the bushes d d of the center plumber-block. Thus the two armatures are quite independent of cach other and can turn in opposite directions.

Referring now to Figs. '7, S, and 9, showing the electrical connections, a a indicate two armature-shafts, which are separate from each other, but preferablyin line (see Fig. 1) and interposed between the poles of field magnets or cores B at the opposite ends of said cores, as shown. Cn said cores are a plurality of exciting-coils, arranged iu two `grou ps. In the present example there are four coils in each group, the rs group D D D D being in series with each other and in shunt with the line-circuit and the second group T T T T being in series with each other and with the line. On each side of the center plumberblock P',Fig. l,four of these coilsare arranged, so that ashunt-coil D has facingit on the same core and lying on each side of it on the adjacent cores B B series-wo und coils T, while a second shunt-coil D is opposite it on the opposite core B. The connections from the opposite ends oi' the series group of coils T T T T, from each of the four collectors c c c c of the armature, from the two terminals of the generator H, and from the ends of the shunt group of coils D D D D pass to contacts l to 10 on the commutator G. This commutator is of any preferred type, and is so arranged as to complete the circuit in three ways, namely: iirst, through the generator I-I, collectors c, and series coils T, Fig. 7, cutting out the shunt-coils D; second, through the generator TI, collectors c, and shunt-coils D, Fig. 8, cutting out the series coils T, and, third, through the generator H, collectors c, and series and shunt-coils Tand D, Fig. 9.

The motor works as follows: The eight coils are arranged, as shownin Figs. 3 to, four on each side of the central pliiznber-blocl ,so that a coil D with shunt-winding has facing it and on each side a series-wound coilT and another shunt-coil D diametrically opposite it. Thus there is obtained a perfectly symmetrical and balanced magnetic field,whatever the manner of excitation, be it series or shunt, employed separately or simultaneously. The magnetic circuits excited by this lield are four in number, proceeding symmetrically from a north pole N to a south pole S, passing through the armatures and the cores, where they are sub- IOO mitted to the influence of two coils D and two coils T. The two armatures are always in the same magnetic field, whatever may be their electrical coupling obtained by the combination and whatever be the coupling of the two excitations, series or shunt, employed separately or simultaneously. The differential character of the motor is thus obtained by the difference of the angular speed of each armature, accordingly as that of the motor-wheel, which is connected with the shaft of the armature, is more or less varied by the traveling of the vehicle around a curve.

Having thus described the nature of this invention andthe best means I know for carrying the same into practical effect, I claiml. In an electric vehicle, the combination of two independent shafts, each driving a wheel of the vehicle, two armatures on said shafts, and field-magnets acting upon these armatures in which the magnetic fields are symmetrical and in equilibrium.

2. In an electric vehicle, the combination of two independent shafts, each driving a wheel of the Vehicle, two armatures on said shafts, and a lieldmagnet for said arm atu res containing a plurality of exciting-coils arranged in two groups having each the same number of coils, one of said groups being shunt-wound and the other of said groups being serieswound, and means for connecting each of said groups separately to the generator.

3. In an electric vehicle, the combination of two independentshafts each driving a wheel of the vehicle, two armatures on said shafts, and a field-m agnet for said armatures con taining a plurality of exciting-coils arranged in two groups having each the same number of coils, one of said groups being shunt-wound and the other of said groups being serieswound, the arrangement being such that a shunt-coil faces and has on each side of it a series coil while diametrically opposite to it is another shunt-coil, and means for connecting each of said groups separately or simultaneously to the generator.

4. In an electric vehicle, the combination of two independent shafts which are in line with each other, and each of which drives a wheel ot' the vehicle, two armatures on said shafts, and field-magnets acting upon these armatures in which the magnetic fields are symmetrical and in equilibrium.

In an electric vehicle, the combination of two independent shafts which are in line with each other and each of which drives a wheel of the vehicle, two armatures ou said shafts, anda field-magnet for said armatures containing a plurality of exciting-coils arranged in two groups having each the same number of coils, one of said groups being shimt-wou nd and the other of said groups being serieswound, the arrangement being such that a shunt-coil faces and has on each side of il a series coil while diametrically opposite to itis anothersh u n t-coil,su bstan tially as described.

6. An electric motor comprising two armatures keyed on separate shafts which are in line with each other, and eight exciting-coils arranged four on each side of the central bearing for the two shafts, four such coils being identical and shunt-wound while the other four are identical and series-wound, the arrangement being such that a shunt-coil faces and has on each side of it a series coil while diametrically opposite to it is another shuntcoil, substantially as described.

In witness whereof I have hereuntosigned my name in the presence of two subscribing witnesses.

CHARLES MILDE.

Vitnesses:

JULES ARMENGAUD, Jeune, EDWARD I. MACLEAN. 

